In recent years, a hybrid vehicle, an electric vehicle and the like that uses electric power of a battery or the like to drive a driving wheel are attracting attention for environmental considerations.
In recent years, in particular, it is attracting attention to allow such a battery mounted, electrical powered vehicle as described above to have the battery charged without using a plug or the like or contactlessly, i.e., wirelessly. For example, Japanese Patent Laying-Open No. 2007-252027 describes a contactless charging system including: a battery incorporated, movable device; a power receiving unit provided in the movable device; and a contactless power transmitting device to supply the power receiving unit with electric power. The power receiving unit includes a power receiving coil, the contactless power transmitting device includes a power transmitting coil, and electric power is transmitted from the power transmitting coil to the power receiving coil through electromagnetic induction.
Furthermore, a wireless power transfer system exploiting electromagnetic resonance is described for example in WO2010/041321 describing a power transfer system. The power transfer system includes a power receiving device and a power transmitting device, and the power transmitting device includes a shield, a power transmitting coil disposed inside the shield, an electromagnetic induction coil disposed inside the shield, and a rectifier disposed inside the shield. The power receiving device includes a shield, a power receiving coil disposed inside the shield, and an electromagnetic induction coil disposed inside the shield.